The present invention relates to location detection and, more particular, to location detection of electronic devices in indoor environments.
In many outdoor environments, the Global Navigation Satellite System (GNSS), of which the Global Positioning System (GPS) is a part, provides locations for electronic devices, such as mobile terminals, with an accuracy of around 15 meters. These types of systems use satellites to function, and, in obstructed outdoor and indoor areas, the satellite signals may be too weak to enable accurate positioning. One approach to performing indoor location detection is to place a radio frequency beacon, such as a BLUETOOTH™ low energy beacon, at suitable locations in the indoor facility. Placing one beacon in each room, for example, may theoretically provide room level accuracy of the location of a mobile device by scanning for hearable beacons and selecting the one with the strongest signal as the indoor location. In practice, radio waves and multi-path components from beacons in other rooms can in many cases be stronger than the beacon in the room that the user of the mobile terminal is in. To address this problem, trilateration of several hearable beacons and/or fingerprinting algorithms based on signal strength reference data collected may be used. These fingerprinting techniques may be sensitive to environmental or people density changes and may require periodic recalibrations of the reference data. Techniques using beacons that transmit audio signals, such as ultrasound signals, may also be used for device location detection, but these techniques may be limited as the ultrasound signals may be blocked by walls or other structures. Moreover, the ultrasound signals may have bandwidth limitations that may make it more difficult to transmit data to uniquely identify a transmitting beacon.